From 92dbf98339dd421bdbb4342f4980728e5f4ba3a4 Mon Sep 17 00:00:00 2001
From: Andrew Tomaka <atomaka@gmail.com>
Date: Thu, 8 Oct 2015 18:03:09 -0400
Subject: [PATCH] Null object pattern for User as GuestUser

---
 app/controllers/application_controller.rb |  3 ++-
 app/models/user.rb                        | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 803363f..2c0b2b9 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -10,9 +10,10 @@ class ApplicationController < ActionController::Base
 
   def current_user
     @current_user ||= User.find(session[:user_id]) if session[:user_id]
+    @current_user ||= GuestUser.new
   end
 
   def logged_in?
-    @logged_in ||= !!current_user
+    @logged_in ||= current_user.class.name.demodulize == 'User'
   end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 6480f19..458c5c9 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -26,3 +26,13 @@ class User < ActiveRecord::Base
     self.add_role :admin
   end
 end
+
+class GuestUser
+  def admin?
+    false
+  end
+
+  def moderator?
+    false
+  end
+end